Vibration Characterisation of Strollers and Cargo Bicycles for Transporting Infants

Including Recommendations for Users, Designers, Manufacturers, and Researchers

Abstract

Infants are transported in strollers and in baby seats mounted in cargo bicycles. The infants experience whole-body vibration during the associated walking and cycling trips, but there is little existing knowledge about associated comfort and health effects. To improve this, we measure the seat pan acceleration of five strollers and two styles of cargo bicycles with dummy infants representing ages 0 to 9 months over six different road surfaces of varying road roughness at typical travel speeds. The five strollers included three modern systems and two vintage systems with some level of suspension. One cargo bicycle had electric support enabling speeds up to 25 km h−1. We report average seat pan acceleration for 78 different scenarios and investigate the effects of road surface, vehicle, seat type, and travel speed. Using the whole-body vibration ISO standards, we show that rough road surfaces, amplified by travel speed, may have health risks for travel durations as low as 10 min to 30 min. Stroller designs from 50 years ago significantly reduce vibrations, relative to most modern strollers we tested, indicating the need for return of suspension elements. Cargo bicycles ridden at the maximum electric bicycle speed over paver bricks can cause accelerations that should likely be avoided except for only the shortest of durations until more direct evidence of risks to infants is studied. Standards are needed for infant transport testing and evaluation, designers need to incorporate better suspension for infants, and research is needed to develop clear and direct connections to health and comfort effects.